The "t-value" is a statistic used in hypothesis testing, particularly in the context of the t-test. It helps determine if there is a significant difference between the means of two groups. The t-value is calculated by taking the difference between the group means and dividing it by the standard error of the difference. A higher t-value indicates a greater difference between the groups relative to the variability in the data. In statistics, the t-value is compared to a critical value from the t-distribution table, which depends on the desired significance level and the degrees of freedom. If the t-value exceeds the critical value, the null hypothesis can be rejected, suggesting that the observed difference is statistically significant.